It may be as well to start with what Vine has to say concerning the meaning of the underlying Greek word translated as DISPENSATION, ADMINISTRATION OR STEWARDSHIP. His comments are as follows:-
“OIKONOMIA... primarily signifies the management of a household or of household affairs (oikos, a house, nomos, a law); then the management or administration of the property of others, and so stewardship, Luke 16:2, 3, 4; elsewhere only in the Epistles of Paul, who applies it (a) to the responsibility entrusted to him of preaching the Gospel, 1 Cor. 9:17 (R.V., “stewardship,” A.V., “dispensation”); (b) to the stewardship committed to him “to fulfil the Word of God,” the fulfilment being the unfolding of the completion of the Divinely arranged and imparted cycle of truths which are consummated in the truth relating to the Church as the Body of Christ, Col. 1:25 (R.V. and A.V., “dispensation”) so in Eph. 3:2, of the grace of God given him as a stewardship (“dispensation”) in regard of the same “mystery”; (c) in Eph. 1:10 and 3:9, it is used of the arrangement or administration by God, by which in “the fulnessof the times” (or seasons) God will sum up all things in the heavens and on earth in Christ. In Eph. 3:9 some mss. have koinonia, “fellowship” for oikonomia “dispensation.” In 1 Tim. 1:4 oikonomia may mean either a stewardship in the sense of (a) above, or a dispensation in the sense of (c). The reading oikodomia, “edifying,” in some mss., is not to be accepted. See Stewardship.
Note:A dispensation is not a period or epoch (a common, but erroneous, use of the word), but a mode of dealing, an arrangement or administration of affairs. Cp. oikonomos, a steward, and oikonomeo, to be a steward.”
In the J. N. Darby Bible we have the following words used:-
Dispensation: Colossians 1:25
Administration: 1Corinthians 9:17
Ephesians 3:2, 9
Stewardship: Luke 16:2, 3, 4
Marshall’s literal translation has “Stewardship” in all these cases.
Mr Darby’s note to Colossians 1:25 reads as follows: “Or, ‘economy,’ as ‘administration’ in 1 Cor. 9:17; Eph. 1:10; 3:2, 9; ‘dispensation,’ 1 Tim. 1:4; and ‘stewardship,’Luke16: 2, 3, 4.”
However, having considered what has been written about the meaning of the word dispensation one would go on to what is perhaps usually thought of as dispensations; thus we have:-
(1) The time of innocence – the time that Adam and Eve had in the garden before they sinned; whether that was long or short we are not told. However, there are reasons for thinking it was short, though we need not go into them now.
(2) The time without government when mankind became so lawless that God had to destroy the world by a flood.
(3) The time after the flood when God instituted government, until the giving of the law (Genesis 9:1-7).
(4) The time of law when God gave Israel his commandments. This ended when Christ was rejected.
(5) The time of grace in which we still are, as Paul says; “Ye are not under law but under grace” (Romans 6:14).
One has no doubt that God had those that were his in all the periods from (2) to (5). In (2) there was Abel, Enoch and Noah at least. In (3) there was at least Abraham, Isaac and Jacob as well as Joseph. If one accepts that the Jobab of Genesis 10:29 is the same as the Job in the book of that name, as I am inclined to do, we must include him as one who was probably blessed before the call of Abraham. Then we have many others in the period of the law; such being commented on in Hebrews 11. Today many are being gathered in.
It is clear to me that Scripture makes a clear difference between the old order under the Mosaic law and the present time when we are not under law but under grace. Further, under the Mosaic law Israel had material blessings, that is, an earthly inheritance. This involved those things listed in Deuteronomy 28:1-14. The system of worship was a material one (Hebrews 9:1-10). However, when Israel rejected their Messiah God turned to the nations (Acts 13:46/47; 28:28) and although a Jewish remnant was saved and brought into the assembly (Romans 11:1-6) the rest were blinded (Romans 11:7-10). However, in a coming day (possibly sooner than we think) Israel will be grafted in again and receive its earthly inheritance (Romans 11: 22-32; Jeremiah 23:1-8). Meanwhile the nations are being gathered into the assembly. The inheritance of the assembly is a heavenly one (Ephesians 1:3; 2:1-10; 2 Timothy 4:18; Hebrews 3:1; 11:13-16; 12:22); hence it will be caught up before the world is judged and Israel given their earthly inheritance (1 Thessalonians 4:13-18). The Christian’s inheritance is “in my Father’s house” (John 14:2 & 3). However, clearly the earth is also going to be inhabited as Christ said: “The meek... shall inherit the earth” (Matthew 5:5 and consider also chapter 25:34). In fact there will always be an earth as there will always be a heaven so that Scripture speaks of new heavens and a new earth (2 Peter 3:13 and Revelation 21:1).
Some I understand do not think that Israel will be taken up again. I think part of the reason may be that they can see that there is a correspondence between the materialthings spoken of in the Old Testament and their spiritual equivalents in the New (Hebrews 9:11). See also what Peter says in 1 Peter 2:4/5. All this is in accord with what Christ said to the woman of Samaria in John 4:21-24. However, there is both a heavenly and an earthly company (Genesis 22:15-18), just as there is a heavenly seed as well as an earthly one (Galatians 3:29; Romans 9:1-5).
Certainly, Israel will be taken up again on the ground of mercy as we have (Romans 11:30 & 31), but although the assembly like Enoch will be translated before the coming judgment on this earth, Israel like Noah and his family will go through it, that is, God will preserve a remnant in it (Zechariah 14).
I would make the point here that although we are not under the Law of Moses there are things we can learn from it, otherwise there would be little if any point in reading it. However, although we are not under the law we are to be subject to Christ (a person rather than a set of rules). This can be demonstrated from such Scriptures as John 3:36; Matthew 11:29/30; 1 Corinthians 9:21; Acts 3:22/23.
As to saints in Old Testament times I certainly believe that they all had faith, for without faith it is impossible to please God (Hebrews 11:6). Curiously the word faith only appears once in the Old Testament (Habakkuk 2:4) though we know from Hebrews 11 that the Old Testament saints had it. Abraham believed God which showed he had faith. However, the Old Testament saints believed in God, but they could not, I think, be said to believe in Christ. Christ said to his disciples when he was going away; "Ye believe on God, believe also on me" (John 14:1). In the New Testament persons believed in Christ when He was on earth (Matthew 18:6; John 2:11), though they would not have known about his finished work because it had not then been accomplished. Now we are to believe on Him who we cannot see (1 Peter 1:8). In the Old Testament most had not faith (Hebrews 4:2; 3:14-19).